1. Technical Field
This invention relates to a system and method for detecting when an operator performing tasks which require alertness, such as a vehicle operator, air traffic controller, and the like, is impaired due to drowsiness, intoxication, or other physical or mental conditions. More particularly, the present invention employs an eyeblink analysis to accomplish this impaired operator detection. Further, this system and method includes provisions for providing a warning when an operator is determined to be impaired.
2. Background Art
Heretofore, a detection system employing an analysis of a blink of an operator's eye to determine impairedness has been proposed which uses a eyeblink waveform sensor. The sensor is of a conventional type, such as an electrode presumably attached near the operator's eye which produces electrical impulses whenever the operator blinks. Thus, the sensor produces a signal indicative an eyeblink. The proposed system records an eyeblink parameter pattern derived from the eyeblink waveform of an alert individual, and then monitors subsequent eyeblinks. Parameters derived from the eyeblink waveforms generated during the monitoring phase are compared to the recorded awake-state parameters, and an alarm signal is generated if an excessive deviation exists.
Another impaired operator detection system has been proposed which uses two illuminator and reflection sensor pairs. Essentially the eye of the operator is illuminated from two different directions by the illuminators. The sensors are used to detect reflection of the light from the illuminated eye. A blink is detected by analyzing the amount of light detected by each sensor. The number and duration of the detected blinks are used to determine whether the monitored operator is impaired.
Although these prior art systems may work for their intended purpose, it is a primary object of the present invention to provide an improved and more reliable impaired operator detection and warning system which can provide a determination of whether an operator is impaired on the basis of eyeblink characteristics and thereafter initiate an impaired operator warning with greater reliability and accuracy, and via less intrusive methods, than has been achieved in the past.